The measurement resulting from dividing a urinary calcium concentration by the urinary creatinine concentration provides a valuable metric for assessing calcium excretion relative to kidney function. For example, a patient with hypercalcemia may undergo this analysis to evaluate if the kidneys are appropriately excreting calcium or if there is abnormal calcium retention. The resulting value is often expressed as a ratio, such as milligrams of calcium per gram of creatinine.
This metric is particularly useful in the evaluation of certain medical conditions, including kidney stone formation, parathyroid disorders, and idiopathic hypercalciuria. The assessment of calcium excretion relative to creatinine allows clinicians to better understand calcium handling by the kidneys. Its clinical application dates back several decades, contributing significantly to the diagnostic and monitoring strategies for various metabolic and renal disorders.